af65207c76
ea_inode feature allows creating extended attributes that are up to 64k in size. Update __ext4_new_inode() to pick increased credit limits. To avoid overallocating too many journal credits, update __ext4_xattr_set_credits() to make a distinction between xattr create vs update. This helps __ext4_new_inode() because all attributes are known to be new, so we can save credits that are normally needed to delete old values. Also, have fscrypt specify its maximum context size so that we don't end up allocating credits for 64k size. Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
138 lines
3.0 KiB
C
138 lines
3.0 KiB
C
/*
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* fscrypt_common.h: common declarations for per-file encryption
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*
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* Copyright (C) 2015, Google, Inc.
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*
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* Written by Michael Halcrow, 2015.
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* Modified by Jaegeuk Kim, 2015.
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*/
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#ifndef _LINUX_FSCRYPT_COMMON_H
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#define _LINUX_FSCRYPT_COMMON_H
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#include <linux/key.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/bio.h>
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#include <linux/dcache.h>
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#include <crypto/skcipher.h>
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#include <uapi/linux/fs.h>
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#define FS_CRYPTO_BLOCK_SIZE 16
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struct fscrypt_info;
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struct fscrypt_ctx {
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union {
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struct {
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struct page *bounce_page; /* Ciphertext page */
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struct page *control_page; /* Original page */
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} w;
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struct {
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struct bio *bio;
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struct work_struct work;
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} r;
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struct list_head free_list; /* Free list */
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};
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u8 flags; /* Flags */
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};
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/**
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* For encrypted symlinks, the ciphertext length is stored at the beginning
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* of the string in little-endian format.
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*/
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struct fscrypt_symlink_data {
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__le16 len;
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char encrypted_path[1];
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} __packed;
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struct fscrypt_str {
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unsigned char *name;
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u32 len;
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};
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struct fscrypt_name {
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const struct qstr *usr_fname;
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struct fscrypt_str disk_name;
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u32 hash;
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u32 minor_hash;
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struct fscrypt_str crypto_buf;
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};
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#define FSTR_INIT(n, l) { .name = n, .len = l }
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#define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len)
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#define fname_name(p) ((p)->disk_name.name)
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#define fname_len(p) ((p)->disk_name.len)
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/*
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* fscrypt superblock flags
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*/
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#define FS_CFLG_OWN_PAGES (1U << 1)
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/*
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* crypto opertions for filesystems
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*/
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struct fscrypt_operations {
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unsigned int flags;
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const char *key_prefix;
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int (*get_context)(struct inode *, void *, size_t);
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int (*set_context)(struct inode *, const void *, size_t, void *);
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int (*dummy_context)(struct inode *);
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bool (*is_encrypted)(struct inode *);
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bool (*empty_dir)(struct inode *);
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unsigned (*max_namelen)(struct inode *);
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};
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/* Maximum value for the third parameter of fscrypt_operations.set_context(). */
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#define FSCRYPT_SET_CONTEXT_MAX_SIZE 28
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static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
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{
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if (inode->i_sb->s_cop->dummy_context &&
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inode->i_sb->s_cop->dummy_context(inode))
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return true;
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return false;
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}
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static inline bool fscrypt_valid_contents_enc_mode(u32 mode)
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{
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return (mode == FS_ENCRYPTION_MODE_AES_256_XTS);
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}
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static inline bool fscrypt_valid_filenames_enc_mode(u32 mode)
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{
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return (mode == FS_ENCRYPTION_MODE_AES_256_CTS);
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}
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static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
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{
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if (str->len == 1 && str->name[0] == '.')
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return true;
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if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
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return true;
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return false;
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}
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static inline struct page *fscrypt_control_page(struct page *page)
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{
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#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
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return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
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#else
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WARN_ON_ONCE(1);
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return ERR_PTR(-EINVAL);
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#endif
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}
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static inline int fscrypt_has_encryption_key(const struct inode *inode)
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{
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#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
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return (inode->i_crypt_info != NULL);
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#else
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return 0;
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#endif
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}
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#endif /* _LINUX_FSCRYPT_COMMON_H */
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